At the bottom of the page, put another call to action. Sure, someone can always scroll up but if they've read through the entire page, a concluding sign up button with another push to sign up should give you at least a few more conversions. Also, I'm too lazy to check, but I believe this is the same site that had review for it's original page a while back that was completely locked down and confusing. If so, this is a HUGE improvement! Congrats!